1. Field of the Invention
The present invention relates to navigation systems, and more particularly, to a navigation system and method implemented by radio frequency identification (RFID) technology.
2. Description of the Prior Art
Visitors who have parking spaces reserved may fail to find their reserved parking spaces just because they get lost in the parking lots while taking complicated routes therein. Drivers leaving large parking lots manage to find toll collection booths after taking routes longer than what is required, though the drivers may even miss exits and thereby waste their time. Looking for things to buy in large shopping malls with complicated routes is the most annoying shopping experience, which is especially true where, in the shopping malls, walkways are not straight and routes are not invariable, not to mention that walkway layouts vary from floor to floor, making it difficult for shoppers to locate their target merchandise. Once a movie or performance starts, latecomers will have to grope their way in the dark. The aforesaid situations are always embarrassing. It is much easier to go to a target location, using a device that advises users at crossroads which way to go and indicates the distance and the direction the users should preferably go before reaching the target location.
Over recent years, use of global positioning systems (GPS) is no longer restricted to the military, but is becoming more civilian-oriented, involving international airlines, maritime services and rescue operations; global positioning systems are widely used in terrestrial navigation systems, and vehicular navigation systems especially. In general, a vehicular navigation system entails using a GPS module installed in a vehicle to display route maps, for example, the best driving route and the shortest driving route, on a display panel in accordance with inbuilt maps, immediately after data about a current location and an intended destination are entered into an operating panel. Once a driver strays from a course indicated in a route map displayed on the display panel, the driver will have to reenter the data about the current location and the intended destination in order to allow the GPS module to work out the recommended driving route anew. Of course, it is dangerous to reenter data while driving. Similarly, it is a waste of time stopping a vehicle in order to reenter data, and it is inconvenient to do so especially when the traffic is too heavy to allow the driver to stop the vehicle for even a short while. Furthermore, considering the preciseness of GPS observation nowadays, GPS are best used in large spaces, for example, national highways, provincial highways, county routes, and roads. By contrast, it is infeasible to use GPS in small predetermined spaces (for example, parking lots), because small geographic spaces require relatively precise GPS data. But GPS which are relatively more precise are relatively expensive. Hence, GPS are presently not used in small spaces.
Radio frequency identification (RFID) is a kind of identification technology that rests on an embedded chip, tag, transceiver, and backend system middleware. With a chip emitting radio waves, RFID allows a network to gain access to related data such that objects are identified, tracked down and managed. RFID involves using radio waves for transmitting any identification data required for identification. A RFID system comprises three major components, namely an antenna, transponder (or tag), and transceiver (or reader). A transponder, also known as a tag, comprises a tiny chip and an antenna. A battery-powered transponder is generally referred to as an active tag. An active tag is characterized by a large memory and long read distance, though the active tag has its own drawbacks, namely high prices, and a mere 7 to 10 years of battery life. A transponder is generally referred to as a passive tag when powered by inductive coupling. A passive tag has a small memory, and its advantages are, namely competitive pricing and having a unique identification code. The primary purpose of a transceiver is to receive instructions from a host computer and send back data stored in the transponder to the host computer in a wired (for example, by RS422 or Ethernet) or wireless manner. A transceiver comprises a controller and an antenna. A transceiver for long distance read is typically equipped with an individually installed antenna. The aforesaid controller and antenna are not hereinafter described in details, as they are familiar to persons ordinarily skilled in the art.